Strobe Arm Length?

What is the recommended length for strobe arms when doing Wide Angle shooting? RIght now I only have a 6" arm connected to an extended arm mount at the release handle on an Ikelite housing (this is their standard 4086.61 set-up that comes with the DS-125 kit). This has worked great while doing macro work, but I'm thinking I'll want the strobes a bit further away for WA. So what's a good overall length? And am I better off getting a single longer arm or just adding another section to my existing one - like a 4"?

A very popular setup seems to be a 5" arm connected to the housing-side, and an 8" arm on the strobe side. That will usually lay out so that your strobes rest on the camera table when your housing isn't being used.

I personally use 2x 8" sections for each of my arms. That gives plenty of spread.

I used 2 x 12 arms on both sides for wide-angle for years, but I'm shifting to 2 x 8. For me, the change is mostly driven by my shift to different strobes.

I used to use two powerful Ikelite SS200s with wide 100 degree beams. At full power and the right ambient light levels, those strobes will work at distances over 2.5 meter/8 feet for subjects like manta rays and some reefscapes. (The exposure guide on the back of the strobes implies that these strobes will work at 3 meters/10 feet at ISO 100 and f/4.0, though I don't think I ever achieved quite that distance). Anyway, at 8-10 feet, to avoid illuminating crap in the water between the lens and subject with those strobes and their wide 100 degree beams, I really did need more strobe separation than is possible with 8" arm sections. When it all comes together with a wide angle lens and very powerful strobes, longer arms can make it possible to turn medium-vis water into gin (Absolut vodka, whatever).

My SS200s have never gone more than a year without one of them malfunctioning or dying. When they came back from their last trip to Ohio and back (with a $400+ repair bill receipt attached) eight months ago, one was already dead right out of the box full of foam peanuts before I could even take it on a dive. Living in Indonesia, hassling with equipment that I can't rely on is no longer worth it for me.

(So - anybody want to buy a couple of powerful strobes, cheap? Honesty requires me to say that I think both of them are absolute lemons, but they are wonderful strobes on those occasions when they are both working. If you live in the US, maybe the breakdown frequency won't matter. Make me an offer.)

My Inon D200s Sea&Sea YS90DXs don't have anything like the power or spread of the SS200s, but they work, and so far they have kept on working, dive trip after dive trip. (The Inons are pretty new, so that isn't so impressive, but the YS90DXs - originally purchased as a temporary stopgap while my SS200s were on another visit to Ohio - have been going strong for over three years.) With reduced power and narrower beams, I can't shoot from as far away (and with the 10.5 FE on the D2X, I rarely want to anyway). The upshot of moving from Ikelite strobes to the Inons and S&Ss is that the 12 inch arm segments that at one time were central to my style of wide-angle shooting are now irrelevant. 2 x 8 works fine.

I've use the 6" arms that came with the DS125 kits. I add to the Ikelite 9" arm on each side.

I found this give me a great deal of flexibility, especially with wide angle shooting.

I've at times found it difficult (but not impossible) to navigate in confined space wreck dives with the 6+9 setup. I've found that the 9" only on each side much more manageable as it is a) small and B) more solid as it doesn't have any joints in the arms.

Well it definitely sounds like I need to add more length. Looks like most people here are using 2x5 and 2x8. Since I already have a 6" segment I think I'll split the difference and get a second 6" section for each strobe.

Thanks to everyone for their advice. I'll let you all know how it works out.

I'd like to re-awaken this topic and ask if those of you who are using dual strobes with double arm segments for each, have compared your results to what you'd obtain with only single arm segments. Roberts' comments related to the strobes he used are helpful, and I'm trying to decide how I'd best like to go for my new DX200 rig with dual Inon Z240s.

My past experience has been only with a Nikonos V, rigged with a large SB102 on a ULCS 8"/8" arm combo, and a small, slaved YS30TTL Duo strobe for fill on a single ULCS 12" arm. The photo below depicts this setup, and typically I'd spread the strobes out wider and lower than shown here. Given the size of the SB102, I liked the double segment arms for getting the strobe away from me, and its spread with the diffuser still was enough to cover the UW-Nikkor 15mm lens. Meanwhile, the S&S strobe just gave me some fill that I liked to have at times, such as around ledges where shadows might be an issue.

With the widespread strobe arms, the rig as a whole was obviously more cumbersome, and u/w photo pro Jay Ireland suggested a different setup that I came to greatly favor, taking advantage of the double arms to drop the SB102 down and beneath my camera. almost centered. This was quite compact for the equipment in use and worked especially well when again under a ledge, while for fish portaits the S&S strobe still provided enough top lighting to avoid unnatural-looking shadows.

Now, I'm switching to digital and have just purchased the aforementioned DX200 setup, shown here with the Z740s each mounted on a single ULCS 8" arm.

I've got a pair of 5" arms that I originally anticipated using, yet upon setting the camera up in a dual 8/5 configuration, it seemed overkill. The comments I've seen here, are steering me back toward going that direction, but I'm just looking for any further insight anyone cares to offer. Food for thought is that I'll be shooting with the 10.5mm DX Fisheye as well as the 12-24mm DX Zoom. Also, for those of you shooting dual strobes, do you generally favor a symmetric positioning of your strobes, and do you favor them higher above the camera or lower to each side of the camera? I do realize that sometimere there is an advantage to other positions based upon your surroundings and the type of illumination you're after, but in general, what do you favor?

For the 10.5 I find it best to keep the strobes only out about 1.5 feet and importantly, back a foot. This back a foot or so is critical when shooting people and other close subjects because I often get really close to the people etc. when shooting and with the strobes in a traditional position, one of the strobes often gets too close to the subject or the wreck/reef with can cause a local blow out.

And while I use two arm segments per side on my rig, I would be better off with just one per side as it would mean less wrestling with the strobes to position them after I enter the water.

Keeping the strobes back a foot sounds like good advice for close-ups. With clamps factored in, an 8/5 arm combo might give a 1.5 foot reach, but I'm guessing you've got a pair of 8s or similar on each side?

Peter, (and others)
Can you explain what is the logical to put the strobes relative close specifically with the super wide lens?
I sow also good results in my experiences with the 10.5 and close strobes but can't explain why.

The 10.5 is so wide that you need to get very close to the subject, if your strobes are to wide you won't light it very well, I to have the strobes close, angle in and get very close to the subject, very close!

Re questions on my last post. The strobes are 1 foot back from the front of the lens and out about 1.5 feet and angled OUT slightly.

With this arrangement I'm trying to paint the central part of the shot with light while not getting hot light on the particles right in front of the lens and not blowing out parts of the shot not in the center.

I happen to use a 5" and a 6" arm on each side. But I would probably do as well with single arms and they would be quicker to setup underwater.